Switch back stable branches jobs to focal

[1] Switched jobs to ubuntu jammy, but some of
these jobs also run on stable/branches and these
are broken for various reasons as mentioned in
the associated Bug, let's switch back these job
to ubuntu focal for stable branches.

[1] https://review.opendev.org/c/x/devstack-plugin-tobiko/+/893662
Closes-Bug: #2035578

Change-Id: Ibcf8442b386271f9f660f1470f6f2815e0f73aaf

zuul.d/devstack-tobiko-minimal.yaml

@@ -19,6 +19,9 @@
     parent: devstack
     nodeset: devstack-tobiko-jammy
     voting: true
+    branches:
+      regex: ^(stable/(wallaby|xena|yoga|zed|2023.1)).*$
+      negate: true
     description: |
       Minimal Devstack Tobiko Plugin job.
 
@@ -33,7 +36,7 @@
     roles:
       - zuul: x/tobiko
     timeout: 10800
-    vars:
+    vars: &job_vars
       configure_swap_size: 8192
       devstack_localrc:
         GLANCE_ENABLE_QUOTAS: false
@@ -80,7 +83,7 @@
     pre-run: playbooks/devstack/pre.yaml
     run: playbooks/devstack/run.yaml
     post-run: playbooks/devstack/post.yaml
-    irrelevant-files:
+    irrelevant-files: &irrelevant-files
       - ^.*\.rst$
       - ^doc/
       - ^infrared_plugin/
@@ -90,3 +93,30 @@
       - ^tobiko/tests/functional/
       - ^tobiko/tests/unit/
       - ^Vagrantfile
+
+- job:
+    abstract: false
+    name: devstack-tobiko-minimal
+    parent: devstack
+    nodeset: devstack-tobiko-focal
+    voting: true
+    branches: ^(stable/(wallaby|xena|yoga|zed|2023.1)).*$
+    description: |
+      Minimal Devstack Tobiko Plugin job Stable branches variant.
+
+      This job provides the base for both the single and multi-node
+      test setup. To run a multi-node test inherit from devstack-tobiko
+      job and set the nodeset to a multi-node one.
+    required-projects:
+      - openstack/devstack-gate
+      - openstack/heat
+      - x/devstack-plugin-tobiko
+      - x/tobiko
+    roles:
+      - zuul: x/tobiko
+    timeout: 10800
+    vars: *job_vars
+    pre-run: playbooks/devstack/pre.yaml
+    run: playbooks/devstack/run.yaml
+    post-run: playbooks/devstack/post.yaml
+    irrelevant-files: *irrelevant-files

zuul.d/nodesets.yaml

@@ -1,14 +1,23 @@
 ---
+- nodeset:
+    name: devstack-tobiko-focal
+    nodes:
+      - name: controller
+        # label: ubuntu-focal
+        label: nested-virt-ubuntu-focal
+    groups: &STANDALONE_GROUPS
+      - name: tempest
+        nodes:
+          - controller
+
+
 - nodeset:
     name: devstack-tobiko-jammy
     nodes:
       - name: controller
         # label: ubuntu-jammy
         label: nested-virt-ubuntu-jammy
-    groups: &STANDALONE_GROUPS
+    groups: *STANDALONE_GROUPS
-      - name: tempest
-        nodes:
-          - controller
 
 
 - nodeset: